An “apostille” is a kind of authentication applied to documents that are required for an official purpose in a country that participate in the Hague Convention. In many states, such as Texas, Illinois and Indiana, the Secretary of State performs the authentication service and generates the apostille to the documents of U.S. citizens. Some examples of the types of documents that nearly all translation service companies are familiar with include college diplomas, company bylaws, marriage certificates, divorce decrees, adoption decrees and birth certificates. So what is an apostille? An apostille is a globally understood type of authentication. The primary function of the apostille is to recognize any stamp or seal affixed to an official document. The apostille guarantees that public paperwork issued in one signatory country will be recognized as valid in another signatory country.